/**
 * xrdp: A Remote Desktop Protocol server.
 *
 * Copyright (C) Jay Sorg 2012-2013
 * Copyright (C) Idan Freiberg 2013-2014
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "libxrdp.h"

/*****************************************************************************/
struct xrdp_fastpath *APP_CC
xrdp_fastpath_create(struct xrdp_sec *owner, struct trans *trans)
{
    struct xrdp_fastpath *self;

    DEBUG(("  in xrdp_fastpath_create"));
    self = (struct xrdp_fastpath *)g_malloc(sizeof(struct xrdp_fastpath), 1);
    self->sec_layer = owner;
    self->trans = trans;
    DEBUG(("  out xrdp_fastpath_create"));
    return self;
}

/*****************************************************************************/
void APP_CC
xrdp_fastpath_delete(struct xrdp_fastpath *self)
{
    if (self == 0)
    {
        return;
    }
    g_free(self);
}

/*****************************************************************************/
/* returns error */
int APP_CC
xrdp_fastpath_reset(struct xrdp_fastpath *self)
{
    return 0;
}
/*****************************************************************************/
int APP_CC
xrdp_fastpath_recv(struct xrdp_fastpath *self, struct stream *s)
{
    int fp_hdr;
    int len = 0;
    int byte;
    int hdr_len = 2; /* fastpath header length - can be 2 or 3 bytes long, depends on length */
    DEBUG(("  in xrdp_fastpath_recv"));

    /* read the first fastpath byte
     * (we already received it via iso layer */
    // receive fastpath first length packet
    init_stream(s, hdr_len);
    if (trans_force_read_s(self->trans, s, hdr_len) != 0)
    {
       return 1;
    }
    in_uint8(s, fp_hdr); /* fpInputHeader (1 byte) */

    self->numEvents = (fp_hdr & 0x3C) >> 2;
    self->secFlags = (fp_hdr & 0xC0) >> 6;

    // receive fastpath first length packet
    in_uint8(s, byte); /* length 1 */

    if (byte & 0x80)
    {
      byte &= ~(0x80);
      len = (byte << 8);
      // receive fastpath second length packet
      init_stream(s, 1);
      if (trans_force_read_s(self->trans, s, 1) != 0)
      {
         return 1;
      }
      hdr_len++;
      in_uint8(s, byte); /* length 2 */
      len += byte;
    }
    else
    {
      len = byte;
    }

    g_writeln("len= %d , numEvents= %d, secFlags= %d, bytesleft: %d", len, self->numEvents, self->secFlags, (s->p - s->data));

    // receive the left bytes
    init_stream(s, len - hdr_len);
    if (trans_force_read_s(self->trans, s, len - hdr_len) != 0)
    {
       return 1;
    }
    DEBUG(("  out xrdp_fastpath_recv"));

    return 0;
}
/*****************************************************************************/
int APP_CC
xrdp_fastpath_init(struct xrdp_fastpath *self)
{
    return 0;
}

/*****************************************************************************/
int APP_CC
xrdp_fastpath_send_update_pdu(struct xrdp_fastpath *self, tui8 updateCode,
                              struct stream *s)
{
    tui16 len;
    tui16 maxLen;
    tui32 payloadLeft;
    tui8 fragment;
    struct stream *s_send;
    int compression;
    int i;
    int i32;

    compression = 0;
//    s_send = self->out_s;
    maxLen = FASTPATH_MAX_PACKET_SIZE - 6; /* 6 bytes for header */
    payloadLeft = (s->end - s->data);

    for (i = 0; payloadLeft > 0; i++)
    {
        if (payloadLeft > maxLen)
        {
            len = maxLen;
        }
        else
        {
            len = payloadLeft;
        }

        payloadLeft -= len;

        if (payloadLeft == 0)
        {
            fragment = i ? FASTPATH_FRAGMENT_LAST : FASTPATH_FRAGMENT_SINGLE;
        }
        else
        {
            fragment = i ? FASTPATH_FRAGMENT_NEXT : FASTPATH_FRAGMENT_FIRST;
        }

        init_stream(s_send, 0);
        out_uint8(s_send, 0); /* fOutputHeader */
        i32 = ((len + 6) >> 8) | 0x80;
        out_uint8(s_send, i32); /* use 2 bytes for length even length < 128 ??? */
        i32 = (len + 6) & 0xff;
        out_uint8(s_send, i32);
        i32 = (updateCode & 0x0f) | ((fragment & 0x03) << 4) |
              ((compression & 0x03) << 6);
        out_uint8(s_send, i32);
        out_uint16_le(s_send, len);
//        s_copy(s_send, s, len);
        s_mark_end(s_send);

//        if (xrdp_tcp_send(self->tcp_layer, s_send) != 0)
//        {
//            return 1;
//        }
    }

    return 0;
}

/*****************************************************************************/
int
xrdp_fastpath_process_update(struct xrdp_fastpath *self, tui8 updateCode,
                             tui32 size, struct stream *s)
{
    switch (updateCode)
    {
        case FASTPATH_UPDATETYPE_ORDERS:
        case FASTPATH_UPDATETYPE_BITMAP:
        case FASTPATH_UPDATETYPE_PALETTE:
        case FASTPATH_UPDATETYPE_SYNCHRONIZE:
        case FASTPATH_UPDATETYPE_SURFCMDS:
        case FASTPATH_UPDATETYPE_PTR_NULL:
        case FASTPATH_UPDATETYPE_PTR_DEFAULT:
        case FASTPATH_UPDATETYPE_PTR_POSITION:
        case FASTPATH_UPDATETYPE_COLOR:
        case FASTPATH_UPDATETYPE_CACHED:
        case FASTPATH_UPDATETYPE_POINTER:
            break;
        default:
            g_writeln("xrdp_fastpath_process_update: unknown updateCode 0x%X",
                      updateCode);
            break;
    }

    return 0;
}

/*****************************************************************************/
int APP_CC
xrdp_fastpath_process_data(struct xrdp_fastpath *self, struct stream *s,
                           tui8 header)
{
    tui8 encryptionFlags;
    tui8 numberEvents;
    tui8 length2;
    tui8 updateHeader;
    tui8 updateCode;
    tui8 updateFrag;
    tui8 updateComp;
    tui16 length;
    tui32 size;

    encryptionFlags = (header & 0xc0) >> 6;
    numberEvents = (header & 0x3c) >> 2;
//    xrdp_tcp_recv(self->tcp_layer, s, 1);
    in_uint8(s, length);

    if (length & 0x80)
    {
//        xrdp_tcp_recv(self->tcp_layer, s, 1);
        in_uint8(s, length2);
        length = (length & 0x7f) << 8 + length2 - 3;
    }
    else
    {
        length -= 2;
    }

//    xrdp_tcp_recv(self->tcp_layer, s, length);

    if (encryptionFlags != 0)
    {
        /* TODO decryption ...*/
    }

    /* parse updateHeader */
    in_uint8(s, updateHeader);
    updateCode = (updateHeader & 0x0f);
    updateFrag = (updateHeader & 0x30) >> 4;
    updateComp = (updateHeader & 0xc0) >> 6;

    if (updateFrag && updateComp)
    {
        /* TODO */
        g_writeln("xrdp_fastpath_process_data: updateFrag=%d, updateComp=%d",
                  updateFrag, updateComp);
        return 1;
    }

    in_uint16_le(s, size);
    return xrdp_fastpath_process_update(self, updateCode, size, s);
}